[Polymorphism of plasma cholinesterase in Pyrennees populations. Problems in geographic hematology and...

Plasma cholenesterase is classified among blood markers whose genetic variation in man was discovered during past years. To look broadly at the characteristics of this system two main fields are now well established: geographical hematology and pharmacogenetics. In the present work the results of the study of that enzyme are reported in 2 400 individuals belonging to distinct Pyrenean communities. On geographical hematology the data obtained show the existence of a genetic polymorphism, the extent of which has a significant variation in the different areas. The E1a gene reaches the highest frequency (7.7%) in the central part of the Pyrénées (Lux Saint-Sauveur Valley): the rate decreases in Toulouse (3%) and in the Basques (2.3%). The E1s allele was found in the Basques with a frequency of 2.13% value which gives a peculiar feature to this group when compared to other Pyrenean populations. The E1f gene was seldom discovered in the samples studied. These data fill a gap in mapping the distribution of blood markers in France. On pharmacogenetics, the gene frequencies observed at the E1 locus were used for the likelihood of findings genotypes with a sensitivity to suxamethonium or other chemicals. Such a sensitivity cannot be underestimated in some groups (central part of Pyrénées, Basques). In medical practice a molecular abnormality of cholinesterase may be detected after apnea due to suxamethonium administration during anesthesia or in some cases of toxic syndromes induced by chemical compounds (agricultural or industrial products), inhibition of Cholinesterase.